Superregenerative receiver system



Sept, 13, 1949. F, JAGG] 2,481,517

SUPERREGENERATIVE RECEIVER SYSTEM Filed March l2, 1945 2 Sheets-Sheet 1 FFFF L l t A.: l

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SUPERREGENERATIVE RECEIVER SYSTEM Filed March 12, `1945 2 Sheets-Sheet 2 INVENTOR. EW/5 F MAGGI ATTORNEY Patented Sept. 13, 1949 UNITED STATES PATENT FFICEA v y 2,481,517 y. -v Y l' SUPEREEGENERATIVE RECEIVER SYSTEM Lewis F. J aggi, San Antonio, Tex. Application March 12, 1945, Serial No. 582,380

2 claims. (c1.4 25o-.20) (Granted under the act of March 3, 1883, as

amended April 30, 1928; 370 O. G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to radio receivers and more particularly to an improved wide band panoramic receiver employing superregenerative detection.

Panoramic receivers of older design have been 4characterized by limitations in sensitivity and in breadth of frequency response.

The objects of the present invention comprise the provision of an improved panoramic receiver that minimizes the limitations in sensitivity and in breadth of frequency response which have been objectionable characteristics of the older receivers; and the provision of a panoramic receiver that uses superregenerative detection in its operation and wherein a plurality of superregeneratve detectors are effectually prevented from causing mutual interference with respect to each other in covering supplemental or the same frequency ranges and operating from a common quench oscillator.

Further objects of my invention are to provide means which will permit the operation of multiple band panoramic receivers without interference with one another. It is also an object of my invention to provide means for permitting two normal panoramic receivers that are tuned to neighboring frequencies, or to the same frequency, each to receive signal without the interference that would normally be present due to the strong radiated signal from such receivers.

It is a further object of my invention to provide means whereby a superregenerative receiver and a transmitting oscillator may rapidly alternate in operation without mutual interference.

With the above and other objects in view which will be apparent to those who are informed in the field of radio circuits from the following description, an illustrative circuit for the present radio receiver invention is shown in schematic form in the accompanying drawings, wherein:

Fig. 1 is a circuit diagram of a superregenerative panoramic receiver of two bands; and

Fig. 2 is a circuit diagram of a device that embodies the present invention and that comprises a. pair of superregenerative receivers that may be tuned independently of each other.

A circuit for a panoramic receiver that embodies the present invention is shown in schematic form in Fig. l of the accompanying drawings and is adapted for covering a desired broad range of frequencies by suitable means, such as by 1 the use of at least two receiving detectors I and! that are of supplemental frequency ranges. Suitable means, such as a quench frequency oscillator 3, or the like, is provided in the circuit. This oscillator 3, in addition to its normal function is adapted for substantially preventing harmonies in the outputs from the lower range receiving vdetector from interfering with the proper functioning of the upper frequency range detector end of the panoramic receiver. The oscillator 3 also prevents interference between the detectors I and 2 if they are tuned to the 'same frequency at any time.

The receiving detector I may be assumed to be a low frequency range detector. The receiving detector 2 may be assumed also to have a frequency range that is, higher than the frequency range of the detector I and as having a lower limit which overlaps the upper limit of the frequency range of the detector I so that within the overlapping range the detectors I and 2 are both tuned to the same frequency. The combined ranges of the receiving detectors I and 2 provide the total range of the panoramic receiver that is contemplated hereby. The separate push-pull quench frequency oscillator 3 serves eifectually to minimize or to prevent the harmonics of the low range detector I from interfering with the operation of the high'range detector '2 by exciting the two detectors I and 2 alternately thru the use in rapid succession of alternate half cycles from the quenching voltage. The separate f push-pull quench frequency oscillator 3 also serves to pre'- vent interference between the detectors I and 2 when tuned to the same or neighboring frequencies.

The two receiving detectors I and 2 are usual forms of superregenerative detectors and are provided with individual antennas 4 and 5, respectively, by means of which intercepted signals are fed to the detectors I and 2. The push-pull oscillator 3 is also of usual form and provides an extlernally supplied quench signal to the detectors and 2.

Individual panoramic sweeps for the detectors I and 2 are provided in any desired manner, as by being covered by the rotatable continuously variable capacitors 6 and l, respectively, that are disposed therein. The variable capacitors 6 and 'I are synchronized with each other in any desired manner, as by being driven mechanically by a common motor 8, as indicated by dotted lines that extend therebetween. In a satisfactorily functioning illustrative model of the device the rate of rotation that was maintained for the variable capacitors 6 and 1 was approximately 1200 revolutions per minute.

The resonant circuit that is associated with the capacitor 6 covers the low frequency range as the panoramic sweep of the detector I, and the resonant circuit that is shown with the capacitor 1 covers the high frequency range of the panoramic sweep ofthe detector'Zl y a The output terminals 9 and I0,'from'the low range detector I apply signal to a suitable reproducerror signal presentation device, such as an oscilloscope I I, or the like.

signal to another reproducer or oscilloscope I4.

The two Oscilloscopes I I and Il. areconneeted to Y a sweep voltage generator I5. The sweep voltage The output terminals f I2 and I3, from the high range detector 2,:applyphase upon the two detectors l and 2, the two detectors are not at any time active simultaneously 'and one Aofthe detectors is prevented from generator I5 is driven by the motor 8, as indicated frequency sweeps of the superregenerative detectors t and! are synchronized by operation 'of the common motor 8;

In operation, a signalr that is intercepted by the antenna 'il and' that -is received by the low range detector I' in its panoramic' sweep, isapplied as pulses -of' direct current thru the output terminals 9 and.Y Iii'therefrom on the signal plates or a* cathode rayitube witliinrthe.oscilloscope il, on the screen' of which the signal pulse appears at adennite frequency'reading las apip that exf tends from.Y thet ground' line thereon.' The lpan-Vd orarni'c sweep of the receiver I is covered by the rotating variable capacitor yEi that isfdriven by thernotor. i

' A signal that is intercepted by the antenna 5 and is received bythe-high range detector 2,1as itsicondenser 'I sweeps thru'its-frequency' range, is' applied as pulses of direct current thru the output-terminals I'2'and I3 therefrom' to the signalk plates. of a cathode' ray tube part of' the oscilloscope M, on the screen of which the signalY pulse.' appears as a pip that extends from the ground line thereupon atY a deiinite frequency reading that corresponds tov the signal frequency onrtheI cathode ray tube screen. The panoramic Y 4 i Y detect any received signal that appears upon the frequency channel to which the detector 2 is then momentarily tuned; A group of pulses is formed the pulse repetition rate of which is the quench frequency. The envelope of the group of pulses constitutes the pulse that is presented at Ythe terminals I2,.and I3 of thehigh frequency range detector 2. Y Due to the'v rapid rotation of the capacitor 1, the detector 2 tunes to any received signal momentarily and the duration of the pulse corresponding to the signal is Vvery short.

Since the' quench voltage appears in opposite picking up the oscillations of the other detector. In the' absence of thisprovision, any oscillations inthe lower Vfrequency range detector I Wouldl put out upper harmonics, or for that matter rfundamentals, that might iall within the detection range ofthe upper frequency range vdetect'in" 2. rlFhese harmonics would bedetec'ted by the de tector 2 and would' appear as indicatieh's! of! site ternal signals received. These harmonics' siginals would, in fact, be false signals since".they would originate within the circuit. By eausilfit, the Vrquench frequency to alternaten bet-'ween the two detectors i and 2, as provided herebyeach detector Vis active over timev intervals of the' saine length and for as muchoft'h'e Vtime' as'thi the V other detector were not present. Y

sweepY of the receiver 2 isco'vered by the rotating` variable capacitor 'I thatis driven. by the motor Il.` The frequency sweeps of Vthelsuperregenera-V tive detectors i and 2v and the time bases of the oscilloscopes II and Mare alli'synchronized sin'ce the' variable capacitors-*Sand I and the sweep voltage generator I5 are driven` :in common by themotor. 1 J -I' The quench signal thatjis developed by the push-,pull oscillator 3 appears acrossthe termi'- nals' I6 and I'I as an alternating voltage that is balanced to ground and4 that is superimposed upon the Ypositive direct plate supply voltage for the detector I andthey detector 2. The plate voltage andthe quench signal' forfthe' low range detector I are supplied fromV theY terminal' I 6'. The plate voltageandn the quench signal' for the highrange detector 2 are supplied-from the terminal I 'I. In both cases return is through ground. For'receiving signals of fifty rnegacy-Y cles frequency and' above, it has beendeterminecl andi noY regenerative detection takes place.- Dur2 Y ing this same half cycle, the quench frequency signal-on the terminal I'l is positive. and thehigh erfrequency range detector: 2' will regenerativel-'y Y Two normal superregenerative receivers I'and i9 which receive their' quench Vsignals' ini-push?- puil from Vquench 'oscillator' V3v arev shown" in Fig; 2-of the drawings'. l f 'y i i 'v The circuit thatis-shown'in Fig; 2 differs from thatv shown inFig.V l in'tliat receivers I8= dhd49 are single-signal receiversandrnot panoramic re'L ceiv'ers as'are the receiversV Vandal. -Eacl`i:i`^"e`` ceiver I8 and I9 maybe tuned independently of the other to a selected'signal; either to a different' signal 'or both to thesamesignal;

Each receiver' I8 Vand I9 is shown-With its ovl/'ii adjustable B voltage supply 20 and ZI, e'etively. The receivers i8 andl are fedfyqu nc signal output froth` an oscillator Y22 thru the'c'on- Vdensers 23 .and 2li, respectively. Signal!is'inte'r The quench voltage that is fed frornithe-oseil'- lator 22 to the receivers Vl tand'I 'isfinade toserve a useful-purpose in bothV phases Voiits=cycle- In one-half ofthe quench vol-tage cyclethe receiver I8 is receiving' and"` the/receiver i9 is blocked. In the other half of the quench` voltage cycleV the receiverv I9-is receiving and the receiverl ItlfisY blocked. There 'is' no Vinter-ference with the re"- eeption ofv signal'by' onevrecei'v'e'r due toy the oscillation of the other receiver.

The circuit of *the receivery I9 may equally well be considered to represent a" transmitting oscillator..;,In this case, due to the alternations. of the blocking-'action bythe quench oscillator' 3f, the

r receiverl I8 continues toreceive. rightthrough a V transmission of the receiver I9 considered -asl a generative detector wouldv not hear even' an er transmitter.A` Y Y It will be'notedthat in' conformity with `the teachings of. the present invention, a superrefserve as a radio interfering transmitter and an observer can listen to signal thru the operations of the oscillator by the use of quench phasing between the detectors or receivers. When so used, the quenched oscillator serves as a superregenerative circuit where only the radiation is used rather than Where it is used as a detector. The quenched oscillator may be extremely high powered and may radiate considerable energy when it is not operating in the quenched portion of the cycle.

It is to be understood that the particular circuits and the particular parts and components that have been shown and described herein have been submitted for the purposes of illustrating and explaining satisfactorily operating embodiments of the present invention, and that modiiications, alterations and substitutions that result in satisfactory devices may be made therein without departing from the present invention as dened by the appended claims.

What I claim is:

1. A panoramic receiver system, comprising in combination a low frequency range superregenerative detector, a high frequency range superregenerative detector supplementing the range of the low frequency range detector, a presentation device for said low frequency range detector, a presentation device for said high frequency range detector, a sweep voltage generator serving both of said presentation devices, a motor synchronously providing a time base for the two indicator means for simultaneously presentingthe outputs of said detectors, and means for providing a time base for said indicator means synchronously with the frequency sweep of said detectors.

LEWIS F. JAGGI.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,959,281 Willoughby May 15, 1934 2,034,775 Roosenstein Mar. 24, 1936 2,063,534 Wallace Dec. 8, 1936 2,189,549 Hershberger Feb. 6, 1940 2,273,914 Wallace Feb. 24, 1942 2,363,651 Crosby Nov. 28, 1944 2,381,940 Wallace et al Aug. 14, 1945 

